Study finds genetic imprints in three generations of Syrian refugees. Researchers urge caution in interpreting findings and call for replication.
Category: genetics – Page 4
The very public sharing of Gene Hackman and Betsy Arakawa’s health details raises ethical questions over privacy.
You may have heard of the fantastic-sounding “dark side of the genome.” This poorly studied fraction of DNA, known as heterochromatin, makes up around half of your genetic material, and scientists are now starting to unravel its role in your cells.
For more than 50 years, scientists have puzzled over the genetic material contained in this “dark DNA.” But there’s a growing body of evidence showing that its proper functioning is critical for maintaining cells in a healthy state. Heterochromatin contains tens of thousands of units of dangerous DNA, known as “transposable elements” (or TEs). TEs remain silently “buried” in heterochromatin in normal cells—but under many pathological conditions they can “wake up” and occasionally even “jump” into our regular genetic code.
And if that change benefits a cell? How wonderful! Transposable elements have been co-opted for new purposes through evolutionary history—for instance the RAG genes in immune cells and the genes required for driving the development of the placenta and mammalian evolution have been derived from TEs.
New structural markers of memory storage uncovered by Scripps Research may pave the way for new treatments for memory loss. Using advanced genetic tools, 3D electron microscopy, and artificial intelligence, scientists at Scripps Research and their collaborators have identified key hallmarks of lo
Mitochondria play a crucial role in maintaining energy balance and cellular health. Recent studies have shown that chronic stress in neuronal mitochondria can have far-reaching effects, not only damaging the neurons themselves but also influencing other tissues and systemic metabolic functions.
A new study led by Dr. Tian Ye’s research team at the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences (CAS) reveals that chronic mitochondrial stress in neurons promotes serotonin release via TMBIM-2-dependent calcium (Ca²⁺) oscillations, which in turn activates the mitochondrial unfolded protein response (UPRmt) in the intestine. The findings are published in the Journal of Cell Biology.
The researchers found that TMBIM-2 works in coordination with the plasma membrane calcium pump MCA-3 (a PMCA homolog) to regulate synaptic Ca²⁺ balance, sustaining persistent calcium signaling oscillations at neuronal synaptic sites.
What if you could take a picture of every gene inside a living organism—not with light, but with DNA itself? Scientists at the University of Chicago have pioneered a revolutionary imaging technique called volumetric DNA microscopy. It builds intricate 3D maps of genetic material by tagging and tr
Microbial micronutrient sharing, gut redox balance and keystone taxa as a basis for a new perspective to solutions targeting health from the gut
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The first couple of months of life is a critical window for microbiome development. Several factors, such as mode of delivery, diet, environment, and the use of antibiotics, shape a child’s gut microbiota, which can have a profound impact on childhood development and lifelong health. For example, recent studies suggest that infants whose microbiome development is disrupted via cesarean section delivery, early antibiotic use, limited breastfeeding, or other factors are at greater risk for asthma and allergies, respiratory infections, inflammatory bowel disease (IBD), type 1 diabetes, and obesity. Citation 14, Citation 15 The assembly of the infant microbiome is first determined by maternal – infant exchanges of microbiota. Citation 16 Therefore, optimizing the maternal microbiome during pregnancy is likely part of a comprehensive approach to protect and promote the fetus’s health and provide the newborn with a specific microbial inoculum at birth. Citation 14, Citation 17 After birth, maternal breast milk promotes the colonization and maturation of the infant’s gut microbiome. Human milk contains a high concentration of indigestible glycans, known as HMOs which can act as growth substrates for beneficial Bifidobacteria to support the early founder strains of the infant microbiome. Citation 18, Citation 19 In addition, HMOs extert several microbiome-independent mechanism such as serving as decoy receptors to effectively block the attachment of pathogenic bacteria and directly interacting with various receptors. Citation 20 The infant microbiome evolves and diversifies further throughout life in response to whether an infant is breastfed, or formula-fed and which type of formula is used. The weaning period (i.e. the introduction of solid food at around 4–12 months) represents another important window of opportunity to positively impact the development of the microbiome as the bacterial community needs to adapt to digest dietary fibers. Studies linking low gut microbial diversity and the lack of specific bacteria to atopic dermatitis emphasize the first 18 month as a critical window period. Citation 21 Complete gut colonization then occurs within approximately 3 years of life and plays an essential role in further digestion, immunity and neuroendocrine pathway development. Citation 22, Citation 23 In cases where antibiotic treatment is necessary, biotic supplements (i.e. pre, pro, syn or postbiotics) have been shown to lessen the deleterious impact of antibiotics on the infant gut microbiome. Citation 24, Citation 25
In healthy adults, the gut microbiome is fully developed and designed to maintain overall balance while promoting its own survival against environmental stressors, with microorganisms engaging in complex interactions. Recent high-resolution studies examining microbiome composition before, during, and after antibiotic use at the individual gene x strain level demonstrate the remarkable adaptability or ‘fitness’ of gut microbial ecosystems. Citation 26, Citation 27 A healthy and fully functional ecosystem primarily aims to preserve its balance, with ecological diversification playing a crucial role in shaping the genetic structure of resident populations to defend against competition and external disruptors and stressors. Citation 27, Citation 28 Thus, intestinal bacterial ecosystems seem to carry an inherent ecological resilience helping to protect both, themselves and as a consequence their host’s health. This resilience seems to be driven by two main factors: a more diverse microbiome appears generally better at preserving its own balance; Citation 29, Citation 30 and 2) a highly collaborative and interdependent nature of microbial communities seems to play a key role in ecological resilience. In a healthy state, different species work together in a balanced and mutually beneficial way through mechanisms like crossfeeding of various microbial nutrients beyond SCFAs and other forms of metabolic cooperation to stabilize bacterial communities under varying environmental conditions. Citation 31 Understanding these mechanisms across all life stages, from infancy to adulthood to old age, while accounting for the variability in adult microbiome profiles shaped by factors such as genetics, diet, lifestyle, and environmental exposures Citation 32–35 will likely enable the design of better-tolerated and more precise interventions. These interventions could holistically target the functionality of microbiome networks rather than focusing solely on individual species or strains and, thus, allow to tap into the endogenous biochemical pathways that act to maintain bacterial homeostasis.
The large diversity of the adult microbiome, however, presents a notable challenge. A previous comprehensive investigation involving over 1,000 healthy individuals from diverse ancestral backgrounds living in shared environments provided interesting insights. It showed that genetic ancestry has minimal influence on gut microbiome composition. Instead, notable similarities were found in the microbiomes of unrelated individuals sharing the same household with over 20% of the differences in microbiome composition between individuals attributed to factors such as habitual diet, medication use, and anthropometric measurements. Citation 36 This is supported by findings from controlled-feeding studies in humans Citation 35 Citation 37 For example, microbiome composition changed detectably within 24 h of initiating a high-fat/low-fiber vs. a low-fat/high-fiber diet Citation 37 despite entrotype stability.
Researchers from the German Primate Center—Leibniz Institute for Primate Research and the Max Planck Institute of Molecular Cell Biology and Genetics have discovered two specific genes that evolve exclusively in humans jointly influence the development of the cerebrum. They have thus provided evidence that these genes contribute together to the evolutionary enlargement of the brain.
The work has been published in Science Advances.
The results show that the two genes act in a finely tuned interplay: one ensures that the progenitor cells of the brain multiply more, while the other causes these cells to transform into a different type of progenitor cell—the cells that later form the nerve cells of the brain. In the course of evolution, this interplay has led to the human brain being unique in its size and complexity.
Genetic engineering in non-human primates has long been limited by the need for virus-based gene delivery methods. Recently, researchers in Japan successfully used a nonviral system to introduce a transgene—that is, a gene that has been artificially inserted into an organism—into cynomolgus monkeys, which is a species of primate closely related to humans. The paper is published in the journal Nature Communications.
Small animal models such as mice do not fully replicate the complexity of human diseases, particularly in areas like infectious disease and neuropsychiatric disorders. This limitation has made non-human primates an essential model for biomedical research.
However, genetic modification of these primates has been challenging. For example, conventional virus-based methods require specialized containment facilities and are limited in terms of the size of transgenes that the viruses can carry. Also, these methods do not allow for precise selection of modified embryos before implantation.
A joint team of professors—Hajun Kim, Taejoon Kwon, and Joo Hun Kang—from the Department of Biomedical Engineering at UNIST has unveiled a novel diagnostic technique that utilizes artificially designed polymers known as peptide nucleic acid (PNA) as probes. The research is published in the journal Biosensors and Bioelectronics.
The fluorescence in situ hybridization (FISH) technique works by detecting fluorescent signals generated when probe molecules bind to specific genetic sequences in bacteria. This innovative FISH method employs two PNA molecules simultaneously. By analyzing the genomic sequences of 20,000 bacterial species, the research team designed PNA sequences that specifically target the ribosomal RNA of particular species.
The method is significantly faster and more accurate than traditional bacterial culture and polymerase chain reaction (PCR) analysis, and it holds promise for reducing mortality rates in critical conditions such as sepsis, where timely administration of antibiotics is crucial.